I have a query I’m using in my CodeIgniter model to fetch the count of listings of products between particular days. This works fine when there are less items in my table, but there are more than 100,000 entries in my table and to just get the output of 2 days it takes around 3-4 minutes. The longer the from and to days are apart, the more time it takes.
So recently I was asked to upgrade Mysql Version from 5.7 to Mysql 8. After the upgrade, I noticed a strange behavior where the results produced is completely different in both version. Below are the structure and sample data.
I am trying to retrieve latest data from my sql table for each record. There will be duplicate data for each record with some data changes. I need to retrieve the latest timestamped data. Can someone suggest which is the optimum solution in terms of performance. Have seen some solutions with inner joins and sub queries.
Edit: though this solution works for many people it may not be stable in the long run, since MySQL doesn’t guarantee that GROUP BY statement will return meaningful values for columns not in GROUP BY list. So use this solution at your own risk!
There is a table messages that contains data as shown below:
I read many threads about getting only the first row of a left join, but, for some reason, this does not work for me.
I have a two tables colors and color_translations with structure like this:
Suppose I have the following relationship in a legacy system, that could not change it.
So I have a query: (ROW_NUMBER() OVER (PARTITION BY itm.storeID, itm.skuID ORDER BY itm.effectiveDate DESC)) AS rn, Then what I would do is use foreach in the the table then scan if rn is equal to 1, if equal then I will add to a value, so basically I sum all the rows whose rn … Read more
